Sunday, September 19, 2010

Re-Learning Heart Failure Semantics

Thursday, Boston Scientific received word from the FDA, that three of their implantable cardiac defibrillators capable of cardiac resynchronization therapy (CRT-D), or biventricular pacing, have been approved for use in patients with "left bundle branch block who have either mild heart failure or heart failure with no apparent symptoms."

This is an interesting discovery - people can have heart failure without symptoms!

This, of course, flies in the face of most of the definitions of heart failure. Take, for instance, this definition from Mayo Clinic:

How is someone supposed to know that the blood flow needs from the heart are not met if the patient has no signs or symptoms? Saying it another way, does this mean that everyone with left bundle branch block and no symptoms might actually have heart failure?

*Sigh*

The lines of classifying the severity of heart failure have never been clear, despite what our medical coders and researchers would like us to believe.

In reality, in the upstream push to prevent heart failure, MADIT-CRT (the study the FDA cited to reach its approval of Boston Scientific's CRT and CRT-D devices) has demonstrated that intervening BEFORE symptoms occur in patients with weak heart muscles and left bundle branch block can improve mortality and reduce hospitalizations for heart failure. This a good thing.

But what we also have learned is that patient symptoms are immaterial for device implantation any longer in patients with weak heart muscles (EF <= 30%) and left bundle branch block (with QRS width of 130 msec or more) on their EKG. As such, classic symptoms of "heart failure" like shortness of breath, swollen legs, and the like, are also immaterial to qualify for a cardiac resynchronization device.

This makes me wonder if we should still be calling CRT devices "heart failure" devices or rather, "heart preserving" devices.

For now, they'll have to stay "heart failure" devices, despite all of the negative connotations. For whoa to the doctor that forgets to give the diagnosis of at least "Congestive heart failure, NYHA Class I" (or, "congestive heart failure without symptoms") when they ask, pretty please, for permission to implant one of these devices from our insurers in our new era of cardiovascular guidelines mandates.

At the VA, in order to get certain restricted drugs you need to have clinical HF. Once had a pt whose private cardiologist ordered Toprol XL for Stage A HF. Had to deny the request since all the pt had was HTN.Perhaps you will need to adopt the STAGE of HF classification when justifying CRT use.CardioNP

This study highlights some of the issues involved with approval of broadening indications for expensive technology without proper vetting of the cost benefit ratios (oh, I forgot; we aren't supposed to pay attention to cost).

There is no indication of the severity of the diagnosed CHF in the patients nor what treatment was required. If all that was needed was an extra dose of furosemide, then one might look at the benefits in a different light vs if all the patients required hospitilization. Also, there is very little indication of how the patients were followed and what their compliance was with other standard therapies, and since the physicians were not blinded to which treatment the patient received (and why exactly did they not blind these physicians to what therapy the patient was receiving?!), there is lots of potential bias that could exist.

The principal funders of the study are none other than Boston Scientific, which enters another potential bias since they are undoubtedly paying the people doing the determiniations and treating the patients. And the folks conducting the study are undoubtedly EP cardiologists who stand to benefit from extensions of the criteria to place these devices.

All show the dangers to allowing expensive technology creep where the FDA does not properly vet the benefits vs the cost (they also are not supposed to consider cost in their decision) and the potential collusion between private industry and the medical establishment who all benefit from this type of research.

Can anyone expalin why they chose not to randomize patients 50% to each group?

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About Me

Westby G. Fisher, MD, FACC is a board certified internist, cardiologist, and cardiac electrophysiologist (doctor specializing in heart rhythm disorders) practicing at NorthShore University HealthSystem in Evanston, IL, USA and is a Clinical Associate Professor of Medicine at University of Chicago's Pritzker School of Medicine. He entered the blog-o-sphere in November, 2005.
DISCLAIMER: The opinions expressed in this blog are strictly the those of the author(s) and should not be construed as the opinion(s) or policy(ies) of NorthShore University HealthSystem, nor recommendations for your care or anyone else's. Please seek professional guidance instead.